Diabetes is a disease that over 340 million people worldwide live with. Daily blood glucose monitoring is essential to management of the disease, as it impacts diet and required medication. Currently, the most accurate method of monitoring involves an often painful finger prick and the drawing of blood. The development of a non-invasive in vivo glucose concentration monitor would make this routine daily practice much more convenient for diabetics.
Methods of noninvasive in vivo glucose detection have been studied for decades but traditional invasive monitors still remain the standard. Prior optical noninvasive in vivo glucose detection studies have been focused on the near-infrared (near-IR) due to the presence of resonant glucose overtone and combination bands combined with low water absorption in that region, which allows for greater penetration of light into skin. However, absorption features of other biological absorbers such as hemoglobin and amides are also relatively broad and strong in the near-IR, leading to the necessity of complex multivariate analysis to extract the impact of only glucose on the spectrum obtained from backscattered light. The unpredictability of concentrations of these other absorbers leads to chance temporal correlations and the need to calibrate data using complex sets recorded over multiple days. Work using Raman spectroscopy with near-IR light has also been reported, but the method has its own obstacles to overcome, such as the relatively weak signal associated with Raman scattering. A non-invasive in-vivo glucose sensor that does not utilize near-IR light is therefore desirable.